As shown in FIG. 1, a conventional foldable display device is two flat plates 1 with a flat structure which are connected to each other by two hinges 3 and have an opening and closing angle of 0 degrees to at least 180 degrees. The grooves on the surfaces of the two flat plates 1 are fitted with a flexible touch screen 2 that can be bent, and the bending line of the flexible touch screen 2 approaches the axis of the hinges 3. The bodies of two flat plates of the prior art foldable display device are connected by the hinges 3 to achieve a folding or flattening opening and closing operation, as shown in FIG. 2. At the time of folding, the flexible touch screen in the foldable display device must also be folded, which cannot be achieved yet using the current flexible OLED (organic light-emitting diode) technology, and if the flexible screen is folded by force or bent excessively, this will most likely cause abnormal screen or screen damage.